The present invention relates to a disk playback device that elastically supports an optical mechanism using a vibration-preventing member.
Various kinds of changer-type disk playback devices (hereinafter referred to as changers) conforming to the DIN standard (ISO 7736) dashboard cavity size (182 mm wide, 53 mm high) for audio devices have been proposed.
Referring to FIGS. 4-6, a changer previously proposed by the present applicant includes a changer having an optical mechanism 10, a holder 20, and transferring means 22. These elements are disposed inside a chassis 25 conforming to the DIN standard dashboard cavity size. Disks held in a holder 20 can be selectively played back.
A base 3 serves as a base for optical mechanism 10. Optical mechanism 10 includes optical reading means such as a turntable 8 and an optical pickup 1. Base 3 is attached to a moving base 9 via vibration-preventing members 15. Moving base 9 is driven by a moving mechanism M1 to move between a playback position P1 shown in FIG. 4 and a recessed position P2 shown in FIG. 5. When moving base 9 is at playback position P1, moving mechanism M1 moves optical mechanism 10 up and down between an upper, mount position where a disk is mounted, and a lower recessed position. Holder 20 can hold a plurality of disks D coaxially and is moved along four vertical shafts 21. Holder 20 is driven by a moving mechanism M2 to transfer the stored disks to appropriate heights. Transferring means 22 drives the edges of a disk using a belt (not shown) to transfer the disk between an insertion/removal position Da, a playback position Dp, and a holding position Ds.
In the above described changer, a disk that is currently in a playback position being played back is transferred to a holding position while a selected disk is retrieved from another holding position and transferred to the playback position. The transfer is performed as follows:
(1) optical mechanism 10 is moved downward away from a disk in a disk playback position Dp;
(2) transferring means 22 moves the disk in the disk playback position Dp to a disk holding position Ds in a holder 20;
(3) optical mechanism 10 is moved back to the recessed position where there is no overlap with the stored disks;
(4) holder 20 is moved vertically to provide alignment with a selected disk;
(5) transferring means 22 moves the selected disk from disk holding position Ds in the holder 20 to the disk playback position Dp;
(6) optical mechanism 10 is transferred to a playback position (a disk mount position) where there is overlap with the stored disks;
(7) optical mechanism 10 is raised and the clamped disk is played back.
The detailed structures of the mechanism and operations performed can be found in Japanese Patent Application No. 9-105135 (U.S. patent application Ser. No. 09/057,209, Attorney Docket No. M1653-119), filed by the present applicant, the disclosure of which is hereby incorporated by reference.
In order to accommodate the DIN standard dashboard size, many design considerations must be contemplated. The above discussed changer was designed such that the optical mechanism 10 must be movable between a playback position that overlaps with the stored disks and a recessed position where there is no overlap. Since the changer requires these two positions of the optical mechanism 10, the size of the changer is determined roughly by (diameter of the disk)+(size of the optical mechanism). Although it is possible to make optical mechanism 10 more compact, the size of optical mechanism 10 is determined by the diameter of turntable 8 and the required range of motion for optical pickup 1. Thus, optical mechanism 10 often tends to be formed with a long shape parallel to the direction of motion of optical pickup 1.
When a changer is installed in a vehicle, external vibrations such as vibrations from the vehicle can lead to frequent read errors during playback of a disk. To prevent the external vibrations from causing read errors, it would be desirable to provide floating support of optical mechanism 10 to the chassis using vibration-preventing members such as dampers or coil springs.
Referring now to FIG. 7 and FIG. 8, vibration-preventing members 15 are disposed at the four corners of the optical mechanism 10. When a vibration affects the changer, the vibration-preventing members may compress or expand in unequal amounts. Along the long axis A1 of optical mechanism 10 a small slope S1 is formed between the base 3 and the moving base 9 due to such external vibration. However, along the short axis A2 of optical mechanism 10 a large slope S2 is formed between the base 3 and the moving base 9. The large spacing of the vibration-preventing members 15 along the long axis A1 and the close spacing along the short axis A2 accounts for the difference in the respective slopes.
As a consequence of the large slope S2, the dimensions of the changer must be altered. It is possible that a vibration may cause contact between the playback disk and the stored disk resulting from the slope S2 along the short axis A2 of optical mechanism 10. The clearance between the playback disk and the stored disks (shown as L1 and 12 in FIG. 6) must be increased to account for slope S2. Similarly, the number of disks stored in the changer must be reduced to prevent damaging the disks.
Accordingly, it is an object of the invention to provide a disk playback device which overcomes the drawbacks of the prior art. In particular, an object of the invention is to provide a compact size disk changer with improved stability of operation.
It is a further object of the invention to provide a disk playback device capable of being mounted in a standard DIN dimension dashboard cavity.
It is another object of the invention to provide a disk playback device of a reduced overall size.
It is a still further object of the invention to provide an improved disk playback device which dampens the effect of vibrations to enhance the quality of data recovery from a disk.
It is yet another object of the present invention is to provide a disk playback device which does not damage surfaces of disks while damping the effect of external vibrations on the disk.
It is a further object of the present invention to provide a disk playback device which prevents contact between disks stored in a holder and a disk in a playback position.
It is still a further object of the present invention to provide a disk playback device which reduces the effects of external vibrations on a disk in a playback position by supporting the disk on a vibrationally damped member.
It is another object of the present invention to provide a disk playback device which reduces the effects of vibrations on a disk being read by an optical mechanism and prevents contact between the disk and stored disks in a holder by supporting the disk with a vibrationally damped member which elastically restricts sloping of the optical mechanism in a direction effected by the vibrations.
Briefly stated, the present invention provides that resilient members absorb vibrations to limit transmission of vibrations from a chassis to a base of a disk record/playback device. A restricting device limits transverse movement of the base on the resilient members. The restricting device limits sloping of a disk mounted on the record/playback device, and thereby prevents interference of the mounted disk with other disks in a storage device. By minimizing the sloping of the disk, the minimum required clearance from the disk mounted on the turntable is reduced and the available vertical space for use in storing disks is maximized. A compact design is possible permitting conformity to constrained dimensions such as standard DIN dimensions in vehicles.
In accordance with these and other objects of the invention, there is provided a disk playback device comprising: a turntable for mounting a disk thereon, an optical pickup movable along a radius of the disk for optically reading information recorded on the disk when the disk is mounted on the turntable, a base extending along a direction of motion of the optical pickup, the turntable and the optical pickup being disposed on the base, a vibration-preventing member elastically supporting the base, and restricting means restricting a sloping of the base along a short side of the base.
The present invention also provides a disk playback device comprising: a turntable for mounting a disk thereon, an optical pickup movable along a radius of the disk for optically reading information recorded on the disk when the disk is mounted on the turntable, a base extending along a direction of motion of the optical pickup, the turntable and the optical pickup being disposed on the base, a plurality of vibration-preventing members elastically supporting the base, and restricting means restricting a sloping of the base along a direction in which a distance between the vibration-preventing members is smaller.
According to a feature of the invention, there is further provided a disk playback device comprising: a turntable for mounting a disk thereon, an optical pickup movable along a radius of the disk for optically reading information recorded on the disk when the disk is mounted on the turntable, the turntable and the optical pickup being disposed on a base, the base extending along a direction of motion of the optical pickup, a vibration-preventing member elastically supporting the base, and restricting means providing elastic restriction of a sloping by the base along a first direction which is effected by an external vibration.
The present invention further includes a device comprising: a chassis, a base having a first axis and a second axis, the first axis being perpendicular to the second axis, the base extending along a direction of the first axis, a turntable for mounting a disk thereon, the turntable being disposed on the base, a vibration-preventing member resiliently supporting the base on the chassis to damp external vibrations and thereby reduce vibrations on the turntable, and restricting means elastically restricting a sloping oft he base along the second axis.
According to a still further feature of the invention, there is further provided a device comprising: a chassis, a base having a first axis and a second axis, the first axis being perpendicular to the second axis, a turntable for mounting a first disk thereon, the turntable being disposed on the base, a holder having a plurality of disks in a storage position, the holder being disposed on the chassis, a vibration-preventing member elastically supporting the base on the chassis such that an external vibration effecting the chassis is damped from the turntable, and restricting means elastically restricting a sloping of the base along one of the first axis and the second axis such that the restricting means prevents the external vibration from causing the first disk to contact the plurality of disks.
According to yet another feature oft he present invention, there is provided a device comprising: a chassis a base having a first axis and a second axis, the first axis being perpendicular to the second axis, a turntable for mounting a disk thereon, the turntable being disposed on the base, a holder having a plurality of disks in a storage position, the holder being disposed on the chassis, a vibration-preventing member elastically supporting the base on the chassis such that an external vibration effecting the chassis is damped from the turntable, restricting means elastically restricting a sloping of the base along one of the first axis and the second axis such that the restricting means prevents the external vibration from causing the first disk to contact the plurality of disks, an optical pickup movable along a radius of the first disk for reading optically recorded information from the first disk mounted on the turntable, the optical pickup is disposed on the base such that the vibration-preventing member reduces the effects of the external vibration on the reading of the first disk, a moving mechanism for moving the base between a mount position, where the first disk is mounted on the turntable, and a recessed position, where the turntable is recessed, and the restricting means includes guiding means allowing the moving mechanism to move the base.
According to another feature of the invention, there is further provided an apparatus for preventing distortion of an optical assembly comprising: the optical assembly being supported on a base, the base extending along a first direction, a plurality of resilient elements supporting the base, and reducing vibration transmission to the optical assembly, and at least one motion-restricting element restricting transverse movement of the base, whereby a sloping of the base along a second direction is reduced.